[SalesForce] the difference between System.currentPageReference() and ApexPages.currentPage()

I couldn't find this properly defined anywhere in docs on when to use System class and when to use ApexPages class to fetch current page reference. Does anyone know if there is actually any difference in using it in different situations?

Best Answer

The two are synonymous. The former is the classic means of accessing the current page, while the new method was introduced as a part of the recent normalization of functions. Other functions have also been duplicated in more appropriate spaces, such as System.Now() vs DateTime.Now() and System.today() versus Date.Today(). It is safe to use either in current code, although one would expect the classic version to be deprecated eventually. Note also that ApexPages.CurrentPage() no longer appears in the documentation, as far as I can tell.

Proof:

Controller

public with sharing class versus {
    public boolean getIsEqual() { return apexpages.currentpage() === system.currentpagereference(); }
}

Page

<apex:page controller="versus">
    {!isEqual}
</apex:page>

Output

true

Conclusion

Since === compares two memory locations, and this operator returning true means that both functions are literally returning the same value.

Related Solutions

[SalesForce] Difference between returning null and ApexPages.currentPage()

The major difference is when you return null the constructors defined in the controller class don't execute.

While if you return whole page the page gets refreshed and constructors get executed only if you have made setRedirect flag set to true.Hence we have an option either to flushout the viewstate or not using this approach.Returning ApexPages.currentPage() will provide us ability to choose set redirect as true or false depending on the business need for the page.

If you are using reRender tags for ajax actions then we prefer null as to avoid whole refresh of page .

[SalesForce] Wrapper class, Rest and json

Assuming the scenario is as simple as you have mentioned in the question you could add the query parameter in the requesturl in your REST call:

url : "SELECT+name,account.name,account.id,Name+from+contact+where+account.activstatus=true"

also set the contentType as "application/json":

 content-Type: "application/json"

This should give you a result in the json format. But you will not get all the records at once, you will get in batches (max 2000). Each response will contain url to which you can make your next request to so as to get the next batch of data..